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Biomedical subjects

S Morgan

Publications and source records attributed to S Morgan.

At least 91 records · Page 5Linked to original sources

Bacteriolytic activity caused by the presence of a novel lactococcal plasmid encoding lactococcins A, B, and M.

Lactococcus lactis subsp. lactis biovar diacetylactis DPC938 was identified as a bacteriocin-producing strain which exhibited a bacteriolytic effect on other lactococci. Lysis of such target strains was associated with decreases in optical density and release of the intracellular enzyme lactate dehydrogenase. DPC938 exhibits cross-immunity to L. lactis subsp. cremoris 9B4 (M.J. van Belkum, B.J. Hayema, A. Geis, J. Kok, and G. Venema, Appl. Environ. Microbiol. 55:1187-1191, 1989), a strain which produces the bacteriocins lactococcins A, B, and M. Genetic analyses revealed that a 15.5-kb region of DNA encoding these bacteriocins is highly conserved in 9B4, DPC938, and DPC3286, an overproducing derivative of DPC938. This region is located on a 72- and a 78-kb nonmobilizable plasmid in DPC938 and DPC3286, respectively. The bacteriolytic effect exhibited by DPC938 and DPC3286 on sensitive cultures is most probably due to the concerted action of all three bacteriocins. Since these cultures exhibit a lytic effect on lactococci, they have a potential application in the dairy industry as accelerators of starter lysis and hence accelerators of cheese ripening.

Amino Acid Sequence↗

Routine urinalysis in renal transplant patients.

The performance of two commercially available urine dipstick tests was evaluated to exclude significant bacteriuria in midstream urine samples from patients attending a renal transplant outpatient clinic. The use of dipsticks to reduce the necessity for routine microscopy and culture was also assessed. Consecutive urine samples (n = 497) from 121 patients were examined for leucocytes, nitrite, and blood with Multistix* 10SG (Ames) and Nephur test (Boehring) dipsticks. All urine samples also underwent routine microscopy and culture. The sensitivities of the Nephur test and Multistix were 83% and 82%, respectively; the specificities were 28% and 40%, respectively; the negative predictive values were 85% and 88%, respectively; and the positive predictive values were 24% and 29%, respectively. Underlying conditions and treatments in renal patients may have led to relatively low sensitivity and positive predictive values. Traditional microscopy and culture methods are more reliable for renal transplant recipients.

Adult↗

Dose rates and energy spectra in the maze of a linear accelerator treatment room.

When designing an entrance maze for a linear accelerator facility, it is useful to be able to estimate both the dose rate at the entrance and, in case further shielding is necessary, the energy spectrum of the scattered photons reaching the maze entrance. This study examines the applicability of the commonly used empirical formula contained in the National Council on Radiation Protection and Measurements (NCRP) Report No. 51 for estimating the dose rates at the maze entrance in a typical treatment room, and proposes an improvement allowing for the fact that the initial scattering event occurs most often in the patient at the isocentre. The X-ray energy spectrum at the maze entrance is also measured and shown to have a lower average energy than is assumed in NCRP Report No. 51.

Algorithms↗

Identifying nursing research priorities: general and neuroscience specific at an acute care hospital.

As a result of economic and health care changes the role of the nurse continues to expand and research-based practice is changing its focus. Limited resources and staff shortages have revealed new areas for research study. Clinical nurses have valuable questions to share that can form the basis of future nursing research. The purposes of the study were to: (a) Determine the priorities for nursing research within a single acute care teaching hospital; (b) Promote nurses' awareness of the importance of research-based practice; (c) Facilitate the development of future nursing research. It was assumed that nurses who carry out direct and indirect patient care roles are "experts" and therefore, are in a position to identify what they see as important questions and in need of further investigation. Three hundred and sixty-six nurses (24%) responded to round #1 of the open ended survey and submitted a total of 912 clinical practice issues. Initially, issues were broadly categorized into clinical and indirect clinical themes in a series of subcategories. Round #2 was conducted to identify nurses' ratings of the priority of the final 123 research issues for future clinical research and practice improvement efforts. Results of the two rounds will be presented, including issues identified by neuroscience nurses. This information will provide a valuable source for additional neuroscience research at either the local or international level.

Acute Disease↗

[Dilatation enteroplasty for obstructive Crohn disease. Experience of the University of Montreal].

Multiple small bowel resections for obstructive symptoms caused by Crohn's disease can lead to a short bowel and malabsorption. Preservation of intestinal length is possible by the use of strictureplasty. Between August 1983 and March 1993, ninety strictureplasties were performed in 25 patients. They were 13 males and 12 females with a mean age of 37 years. Fourteen (56%) previously had small bowel resection for Crohn's disease. A mean number of 4.3 strictureplasties per patient were performed. Concomitant resection of bowel with active disease was performed in 18 patients (72%). In this series, no perioperative death occurred and one patient developed an enterocutaneous fistula. The overall complication rate was 8%. Postoperatively, 18 patients (72%) were completely relieved of symptoms, 6 were improved (24%) and one became worst (4%). After a 27 month follow-up period, the symptoms recurred in 13 patients (52%); three had no treatment, 7 had medical treatment and 3 required reoperation (12%). Our results support the safety and the use of strictureplasty for stenotic bowel lesions associated with Crohn's disease.

Adult↗

MedLine update.

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Animals↗

Screening and monitoring coeliac disease: multicentre trial of a new serum antibody test kit.

A multicentre trial was conducted to evaluate a new test for anti-gliadin antibodies (AGA) in serum (Coeliac Screening Kit, CSK, Medical Innovations Limited, Artarmon, NSW, Australia). The test showed excellent reproducibility for both anti-gliadin IgA and IgG detection. The average intraassay coefficient of variation (CV) was 3.0% for IgA and 2.4% for IgG (n = 6), while the average interassay CV was 6.4% for IgA and 4.3% for IgG (n = 3). By defining a positive test as both IgA and IgG elevated, a sensitivity of 93% in untreated coeliacs (n = 75) was observed. The corresponding specificities in healthy adults (n = 130) and healthy children (n = 77) were > 99% and 100% respectively, while in patients with other gastrointestinal disorders (disease controls) the specificity was 94% (n = 129). The test was also useful in monitoring patients, with anti-gliadin IgA and IgG falling for up to a year after commencing a gluten-free diet (GFD) (12 adults). In some patients however, antibody levels did not reach the normal cutpoint after many months on a GFD, which may reflect the patients' poor adherence to their gluten free diet. The test was superior to the Pharmacia anti-gliadin ELISA, and should be useful as an aid to the diagnosis of coeliac disease, as well as in the follow-up of treated patients.

Adult↗

[Results of anal sphincteroplasty for post-traumatic incontinence: with or without colostomy].

Surgical repair of the anal sphincters after previous trauma is generally successful. In earlier publications, a protective colostomy was recommended but in most recent series colostomy is omitted. We have been through both phases and this is the first comparative study done on 82 consecutive repairs: 45 with colostomy from 1977 to 1986 (Group I) and 37 without colostomy from 1986 to 1992 (Group II). Causes of trauma were obstetrical: 50, surgical: 24 and violence: 5. Apart from colostomy related morbidity, postoperative complication rates were similar in the two groups. Results were graded excellent, good, fair or poor according to continence to solids, to liquids and soiling. Good and excellent results were obtained in 82% (Group I) and 87% (Group II) after a mean follow-up duration of 42 and 23 months respectively. Furthermore there was no difference between Group I and II in the rate of good/excellent results for cases who had undergone prior repairs (98% v. 100%) and also when the duration of incontinence was more than 10 years (71% v. 83%). We conclude that colostomy is not a determinant factor in the outcome and is therefore not required, avoiding all colostomy related morbidity and disability.

Anal Canal↗

Observations of the time-course of the inflammatory response of rectal mucosa to gliadin challenge in gluten-sensitive subjects.

Expression of endothelial adhesion molecules is a key factor in localizing inflammatory processes. We have evaluated the time-course expression of E-selectin, ICAM-1, and VCAM-1 in rectal mucosae from coeliac patients (CD) with T-lymphocyte sensitization to wheat (gliadin) protein. Ten treated, eight untreated CD patients and five disease controls underwent a dynamic 4 h rectal gluten challenge. Seven treated CD patients had a 24 h challenge to evaluate the time-course changes. Coeliac tissue significantly increased VCAM-1 expression [p < 0.001 (untreated and treated CD)] and E-selectin [p = 0.01 (untreated CD only)]-expression compared to controls but not ICAM-1. VCAM-1 continued to increase up to 24 h, while E-selectin decreased after 4 h. These findings relate to a 8 h rise in CD3 (+) lymphocytes [p < 0.05 (treated)] and a 4 h rise in neutrophils (p < 0.005). This approach permits a novel study of the inflammatory response to a known immunogen in human patients.

Celiac Disease↗

Behavioral analysis of asymmetries induced by unilateral 6-OHDA injections into the substantia nigra.

The intent of this study was to perform a detailed analysis of behavioral asymmetries (turning behavior) exhibited by animals which had sustained a unilateral lesion of the substantia nigra (SN). Rats were tested for behavior asymmetries over 16 days, once before, and 7 times after 6-OHDA had been injected into one SN. On the basis of the number of narrow diameter ipsiversive half turns produced during testing, they were then assigned to one of three groups: (a) those which showed an initial asymmetry from which they recovered, (b) those which were asymmetrical throughout testing, and (c) those in which the asymmetry only emerged during the testing period. We examined several different aspects of turning behavior. Recovery from asymmetry was associated with an increase in the number of contraversive, as well as a decrease in the number of ipsiversive narrow-angle turns. The average diameter of these ipsiversive turns also increased. Animals which recovered showed a contraversive asymmetry for wide-diameter turns which increased during testing. Narrow-diameter contraversive turns decreased during testing in the two nonrecovery groups. Both nonrecovery groups showed a contraversive asymmetry for wide-diameter turns. Asymmetry was attributable to a tendency to circle and move ipsiversively in the two nonrecovery groups, whereas it was due to circling behavior in animals which showed recovery. Additionally, more cells, labeled by HRP injected into the ipsilateral caudate putamen, were found in the damaged SN of animals which recovered.

Animals↗

Characterisation of molecular DNA rearrangements within the Xq12-q13.1 region, in three patients with X-linked hypohidrotic ectodermal dysplasia (EDA).

A panel of somatic cell hybrids and X-linked hypohidrotic ectodermal dysplasia (EDA) patient-derived cell lines, containing different rearranged X chromosomes, have been used to refine the physical map of the Xq12-q13.1 region. The patient-derived material included genomic DNA from an EDA male (EDA family 1015) with an interstitial deletion, and a cell line GM0705A, obtained from an isolated female patient with a de novo balanced (X;9) translocation, and the somatic hybrid, AnLy, derived from this cell line. This map subdivides the region into at least 6 mapping-intervals. DNA probes from DXS732 and DXS453, identified as the closest flanking marker loci to the EDA locus, were used to identify homologous Yeast Artificial Chromosome (YAC) clones. Two of the DXS732-specific YACs were shown by fluorescent in situ hybridisation (FISH) analysis to bridge the (X;9) translocation breakpoint. These two YACs were also screened against the ICRF human X chromosome cosmid library and identified 36 cosmid clones. Direct cosmid-cosmid hybridisation analysis placed subsets of these clones within four different cosmid contigs. Mapping of anchor clones from each contig, against the mapping panel, localised all these contigs within the Xq12-q13.1 region. One cosmid, ICRFc104C03.184, identified potential junctional-fragments in several restriction digests of AnLy hybrid DNA. This was confirmed by FISH analysis of the GM0705A cell line with total cosmid ICRFc104C03.184, in which both chromosomal elements of the (X;9) translocation were identified. A single-copy probe pC03.184E2, derived from this cosmid, also identified the der(9)-derived junctional fragment when hybridised against AnLy DNA.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Line↗